A disease is causing pigeons in Russia to fall from the sky, fly into buildings and behave oddly around humans. According to Al Jazeera America, the birds may be suffering from a malady called Newcastle disease.

"Before death they start to act like zombies," one Russian news broadcast said. "They lose their orientation and fly without a sense of direction and then fall, already lacking the strength to get up."

Newcastle disease is a central nervous system ailment that causes apathy, lethargy, disorientation and foaming at the beak.

Some superstitious Russians believe that the dying pigeons signal the end of the world. Grigori Rasputin, Russia's "mad monk" reportedly predicted that the end of the world would come on August 23, 2013.

Watch video about this story, embedded via Al Jazeera America, below: